Obesity ‘may be largely genetic’

Via the Beeb:

Their American Journal of Clinical Nutrition study found that differences in body mass index and waist size were 77% governed by genes.

It strikes me that a more accurate interpretation is that 77% of obesity can be explained by genetic incompatibility with a modern western diet. Genetics dictates the potential for obesity. Everything else is environmental. Send those people off to the savanna with a sharp stick then get back to me.

It’s not a genetic disease like Tay-Sachs, where the mere presence of the genes equals the disease.
Comment by Mark in What to Eat

If this were not the case, the growing epidemic of obesity would imply that obese people are reproducing more, and are hence “genetically fitter,” than those of normal weight. That may be so but seems unlikely. It also means they are poping out babies like crazy over the past 20 years.

Well if it is true, I would like to report that over the Chinese New Year, I’ve mutated slightly and, due to my genetic make-up, I am larger by 1 pound


2 thoughts on “Obesity ‘may be largely genetic’

  1. I agree with you for the most part. I think that the important findings of the study are that most cases of obesity are due to a genetic predisposition to obesity. Therefore, it is not the genetics per se that results in obesity but the combination of genetics and environment, which I think you are illustrating by your example. The one thing we need to remember is that a small percentage of obesity is actually due to genetics (single-gene mutations).

  2. I haven’t stopped by in a while – glad to see you’re still writing.

    And your analysis here is absolutely spot on. All genes are expressed in an environment, because genes are nothing more than the instructions for making a protein – an enzyme or a hormone or a structural protein. An enzyme won’t be used if it doesn’t have a substrate to work on, and substrates come from the environment. Hormones (like insulin) are produced in response to a combination of internal and environmental stimuli. And even structural proteins will not be produced unless there is an adequate supply of amino acids, which come, ultimately, from the environment.

    To paraphrase whats-his-name – it’s the environment, stupid!

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